-
Journal of Neurosurgery Feb 2024The lenticular was an instrument introduced by Galen to facilitate cutting the bone of the cranium. Illustrations of the instrument first appeared in the 16th century...
OBJECTIVE
The lenticular was an instrument introduced by Galen to facilitate cutting the bone of the cranium. Illustrations of the instrument first appeared in the 16th century during the Renaissance. These illustrations have been widely used, but the instrument's shape seems ill-adapted to its function. Archaeological research in Rimini, Italy, unearthed a similar instrument with a shape that seems more suitable for the function of cutting cranial bone. The object of this study was to evaluate the efficacy of these two instruments for cutting the bone of the cranium.
METHODS
Replicas of the two instruments were obtained. Trepanation was performed in the left parietal region of a sheep's head. In addition, the application of the instruments in the literature was analyzed.
RESULTS
The Roman lenticular cut the cranium with ease. The Renaissance instrument failed to cut the bone and only separated the dura mater from the bone. The lenticular had been used to cut bone up to the 13th century. In contrast, the Renaissance instrument was not used to cut bone but to smooth roughened bony surfaces and to remove spicules of bone that were in contact with the dura.
CONCLUSIONS
Analysis of illustrations in medical publications should be undertaken with the same rigor as applied to analysis of text.
PubMed: 38306649
DOI: 10.3171/2023.11.JNS232042 -
Surgical Neurology International 2023Osseous hyperpigmentation of the calvarium is an extremely rare finding with only few reported cases in literature.
BACKGROUND
Osseous hyperpigmentation of the calvarium is an extremely rare finding with only few reported cases in literature.
CASE DESCRIPTION
The case is of a 59-year-old Caucasian male who presented with an acute history of generalized tonic clonic seizures and progressive weakness of the right upper limb. He had a background history of a malignant melanoma which had been resected from his left external acoustic meatus 4 weeks prior. Neuroimaging of the brain showed an intra-axial space-occupying lesion in his left parietal lobe with no associated osseous changes. A left mini parietal craniotomy was performed which revealed black discoloration of the parietal bone. The lesion was successfully resected and the bone flap was secured back in place. The patient was discharged on the 4 day postoperatively with no complications. The unusual finding of black discoloration of the calvarium was found to be secondary to adolescent tetracycline use.
CONCLUSION
Calvarial hyperpigmentation is a phenomenon encountered incidentally and will often come as surprise for surgeons. Once encountered, thorough history taking and examination should be done to investigate the cause.
PubMed: 37680939
DOI: 10.25259/SNI_493_2023